Automatic pencil sharpeners having helical blades and being driven by alternating current are generally actuated by a switch positioned in the sharpener housing near the entry point of the pencil to be sharpened. In operation, the pencil contacts the switch which actuates the motor thereby causing the helical blades to turn and the pencil to be sharpened. Since most alternatingcurrent type motors in automatic pencil sharpeners heretofore available have a low starting or initial torque, it is necessary to position the switch within the sharpener housing near the entry point of the pencil point so that the helical cutting blades are actuated before the resistance of the pencil point is encountered by the helical cutting blades. In this way, the helical cutting blades are actuated without any resistance being offered by the pencil and have sufficient time to develop a cutting torque sufficient to sharpen the point of the pencil when the pencil is pushed past the switch position and into the cutting or sharpening chamber. Because the switch is positioned in the housing near the entry point of the pencil to be sharpened, safety requirements mandate that the wires leading from the switch to the alternating current motor be double-insulated in order to prevent the user from being inadvertently shocked or electrocuted.
Direct-current actuated or battery-operated automatic pencil sharpeners generally have rotating-straight blade type cutting mechanisms rather than helical blade-cutting mechanisms. This is because it has not been practical to use a helical type cutting mechanism in this type of pencil sharpener because of the problem in overcoming starting resistance when a pencil is inserted against the pencil sharpener cutting member.